DESCRIPTION: The prevalence of Alcohol Use Disorder (AUD), Posttraumatic Stress Disorder (PTSD) and co-occurring AUD and PTSD is elevated among Veterans compared to civilians (Carter et al., 2011). Despite available empirically supported treatments, relapse and non-response rates remain high and individuals with co-occurring AUD and PTSD evidence particularly poor clinical and functional outcomes (McCarthy & Petrakis, 2010). Given recent estimates that 63-76% of OEF/OIF Veterans with an AUD also have a diagnosis of PTSD (Seal et al., 2011), there is urgent need to reduce chronic impairment among this growing and highly vulnerable population. AUD and PTSD are characterized by separate and overlapping deficits in attention, memory and higher-order skills known as executive functions (e.g., planning, inhibition, self-regulation), which are in turn, associated with poor clinical and functional outcomes (Bates et al., 2013; Polak et al., 2012, Aupperle, 2012). Indeed, cognitive dysfunction can interfere with many aspects of recovery (e.g. gaining control of maladaptive, over-trained behaviors) and its targeting as a trans-disease process for direct intervention represents a potentially high-yield and innovative approach for optimizing recovery outcomes. Neuroscience-based computerized cognitive training programs for psychiatric illness have achieved growing support in the literature and demonstrate strong potential to remediate disrupted cognitive processes observed in AUD and co- occurring PTSD (Bates et. 2013; Vinogradov et al., 2012). These programs offer a highly accessible, individualized, patient-driven, non-medication treatment approach for improving cognitive functioning. Such improvements may increase emotional and behavioral control and enhance patients' capacity to effectively employ more adaptive self-management strategies. To date however, no studies have capitalized on available evidence-based cognitive remediation technologies to comprehensively target patterns of neurocognitive dysfunction that underlie both AUD and PTSD. The proposed RR&D CDA-2 seeks to fill this gap by conducting a randomized prospective study, designed to evaluate the feasibility and efficacy of an existing web-based cognitive training program (BrainHQ; Posit Science/Brain Plasticity Institute) versus a placebo, for improving cognitive functioning and recovery outcomes. The research will be conducted iteratively, in two stages, based on the Stage Model of Behavioral Therapy Development per the National Institute on Drug Abuse, and has two overarching aims: Aim 1: Examine the acceptability, usability and feasibility of an existing web-based cognitive training program tailored for AUD and co-occurring PTSD. Aim 2: Test the efficacy of the web-based cognitive training program to improve cognitive functioning as well as clinical and functional outcomes. To test these aims, 148 Veterans with AUD and PTSD will be recruited from an outpatient Substance Use Disorder (SUD) treatment program. Participants will be randomized into either cognitive training or a computer game control. Individuals will then complete a baseline assessment, followed by 30 hours of home-based cognitive training or computer games over 6 weeks. Assessments will be completed each week of the training, as well as post-training and at post- training follow-up. Our primary outcome will be performance on an (untrained) neuropsychological assessment battery 6 months post-training. Secondary outcomes include alcohol use, PTSD symptoms and quality of life. Findings from the proposed study will inform clinical practice and policy by investigating whether a cognitive training program (shown to improve cognitive functioning in other clinical populations) can improve cognitive functioning and promote gains in functional recovery from AUD and PTSD. This study will lay the groundwork to investigate the potential for cognitive training to remediate neurocognitive disruptions in other dually diagnosed SUD patient populations across different VA treatment programs. This translational program of research will help vulnerable Veteran populations achieve more optimal and enduring recovery outcomes.